Date   
Re: Antuino now available for purchase

Ashhar Farhan
 

Mike, we calibrate it using a reference 10 mhz by zero beating it. The calibration may slip. It is best to calibrate it with WWV.


On Mon 12 Aug, 2019, 5:16 PM Mike Short, <ai4ns.mike.spam@...> wrote:
One other question. Can the 10 MHz output be used as a frequency source for calibration purposes?

Narrow filter for CW #ubitxcw

_Dave_ K0MBT
 

Hello
I am teaching myself CW and find that the receive filters are too wide even when in cwl or cwu. Many times I hear 3 or 4 signals and it becomes confusing to my new CW ears and older brain.

Has any on designed an IF filter that would be suitable for cw?

I have a v3 and v4 uBITX's Running kd8cec firmware and Nextion displays.

Thanks
Dave
k0mbt

Re: Zero beating / calibration using old Drake method

Jim
 

My wife is still a novice although they changed her call from WN3ZZM to WA3ZZM!

Re: Narrow filter for CW #ubitxcw

Curt
 

Dave

Funny how many of us could do cw with 3 khz or wider filtering decades ago, when a narrow filter cost maybe as much as our receiver.

The design of the ubitx with its bidirectional amplifiers does not easily allow adding a second xtal filter for cw nor IF agc. So think audio filtering.

I use a NESCAF audio filter that features adjustable bandwidth for cw and ssb. And it adds a lm386 audio amplifier output. Mine is external,  but I plan to integrate it. 4state qrp has a narrow cw filter. Kc9on has the CALF audio filter, a bit large but nice audio filter to use with several different rigs.

A cw filter much more important than agc. Being able to easily switch back to ssb is desirable.

Curt

Re: What is the current version board? I have been away from the forum for awhile

Curt
 

Ubitx version 5. It has reduced transmit spurious, and a different audio amplifier.  Still way cool transceiver.

Curt

Re: Narrow filter for CW #ubitxcw

John Seboldt K0JD
 

I tend to like a wide bandwidth for my CW if the interference isn't ghastly. An extra signal peeping along up there at 2 kHz or so doesn't bother me unless it's HUUUGE. I set myself the challenge of doing a CWT contest with the uBITX - stock filtering - and it was do-able - sometimes moving the headphones around helped me discern the wanted signal a little better.

Of course there's a time and place for a narrow filter - really weak stuff or a really busy contest.

I might borrow the one from the QCX - quite nice.

John K0JD

On 8/12/2019 10:29, Curt via Groups.Io wrote:
Dave

Funny how many of us could do cw with 3 khz or wider filtering decades ago, when a narrow filter cost maybe as much as our receiver.

The design of the ubitx with its bidirectional amplifiers does not easily allow adding a second xtal filter for cw nor IF agc. So think audio filtering.

I use a NESCAF audio filter that features adjustable bandwidth for cw and ssb. And it adds a lm386 audio amplifier output. Mine is external,  but I plan to integrate it. 4state qrp has a narrow cw filter. Kc9on has the CALF audio filter, a bit large but nice audio filter to use with several different rigs.

A cw filter much more important than agc. Being able to easily switch back to ssb is desirable.

Curt

Re: Antuino now available for purchase

Sean W7SKD
 

Order placed - looking forward to it.  Thanks Ashar!

Re: Narrow filter for CW #ubitxcw

Richard Spohn
 

See if the Wolfwave audio DSP filter will help. DXEngineering. - Rich WB2GXM

On 8/12/19, _Dave_ K0MBT <davesters@...> wrote:
Hello
I am teaching myself CW and find that the receive filters are too wide even
when in cwl or cwu. Many times I hear 3 or 4 signals and it becomes
confusing to my new CW ears and older brain.

Has any on designed an IF filter that would be suitable for cw?

I have a v3 and v4 uBITX's Running kd8cec firmware and Nextion displays.

Thanks
Dave
k0mbt



Re: Antuino now available for purchase

 

I just ordered one also. Does anybody know where to find the schematic? I saw it somewhere but can't find it now.

Joel
N6ALT

Re: Narrow filter for CW #ubitxcw

Jim
 

If I am remembering correctly my old SP600JX would go down to 200 cycles. You could pull a needle from a haystack with that one. It would sound somewhat hollow. Also remember the astronomical prices of the Collins filters for the KWM series! You could probably buy 3 BITx..for what they cost.

Re: Antuino now available for purchase

Christopher J. Shaker, KJ7BLE
 

Sweet! Thank you very much for offering this.
Chris Shaker

On 8/12/2019 4:34 AM, Ashhar Farhan wrote:
It is a fully tested unit in the all metal case. It has an internal battery case for 6 AA cells. Two SMA connectors.

On Mon 12 Aug, 2019, 5:00 PM Mike Short, <ai4ns.mike.spam@...> wrote:
Does it come with the case?

Re: Antuino now available for purchase

Jerry Gaffke
 

There's an updated schematic in this July 26 2019 post from Farhan
along with a list of changes:    https://groups.io/g/BITX20/message/70551

As he states in that post, it all got archived here:
    https://github.com/afarhan/antuinov2.1

The previous version of the Raduino is found here, last updated in May of 2019:
    https://github.com/afarhan/antuino

Jerry, KE7ER



On Mon, Aug 12, 2019 at 04:08 PM, Joel Caulkins/N6ALT wrote:
I just ordered one also. Does anybody know where to find the schematic? I saw it somewhere but can't find it now.

Re: Narrow filter for CW #ubitxcw

Ashhar Farhan
 

The ubitx has an option for narrow band filter. There are pins to install it. The way it works is a bit of a hack :
1. The CW filter is at a different frequency. Let's imagine it is at 4.915 MHz. It is installed parallel to the 11.059 MHz SSB filter.
2. When choosing CW filter, you have to switch the second conversion oscillator from 56.059 Mhz (45 + 11.059) to 49.915 Mhz (45 +4.915). Shift the BFO to 4.914500 (According to your taste of CW tone).
Apart from designing the crystal filter, this hack is mostly about software changes.

73, f


On Tue 13 Aug, 2019, 4:46 AM Jim, <Jscook@...> wrote:
If I am remembering correctly my old SP600JX would go down to 200 cycles. You could pull a needle from a haystack with that one. It would sound somewhat hollow. Also remember the astronomical prices of the Collins filters for the KWM series! You could probably buy 3 BITx..for what they cost.



Re: Narrow filter for CW #ubitxcw

Evan Hand
 

If you have the KD8CEC software and the Nextion display, using the IF shift and the sideband adjustment, I found that you can shift the received signal to be limited on one edge of the 2.5 khz filter effectively reducing the received bandwidth.  The two controls were designed to filter out unwanted signals.  Worth a try IF you have the Nextion display mod.  

FWIW
73
Evan
AC9TU

Re: Narrow filter for CW #ubitxcw

Jerry Gaffke
 

Looks like PA1FOX has successfully added a second crystal filter for CW:
    https://groups.io/g/BITX20/message/48555
Perhaps Farhan has done this as well.

A perhaps easier hack is to simply add an audio filter for CW, as many here have done.
Some operators will prefer the narrow crystal filter for CW, as this avoids overloading
the receiver audio pre-amp when a strong nearby signal is present.

Evan's hack:  https://groups.io/g/BITX20/message/71042
is well worth trying.  I have not tried the KD8CEC firmware, but should be possible
to implement this with a firmware change only, no Nextion display, no hardware mods.

Jerry, KE7ER


On Mon, Aug 12, 2019 at 06:10 PM, Ashhar Farhan wrote:
The ubitx has an option for narrow band filter. There are pins to install it. The way it works is a bit of a hack :
1. The CW filter is at a different frequency. Let's imagine it is at 4.915 MHz. It is installed parallel to the 11.059 MHz SSB filter.
2. When choosing CW filter, you have to switch the second conversion oscillator from 56.059 Mhz (45 + 11.059) to 49.915 Mhz (45 +4.915). Shift the BFO to 4.914500 (According to your taste of CW tone).
Apart from designing the crystal filter, this hack is mostly about software changes.
 

Re: Narrow filter for CW #ubitxcw

Tom, wb6b
 

Hi,

Are there any comparisons that would indicate if a narrower bandwidth crystal filter verses an audio bandpass filter perform better? In some ways the audio filter is just another filter in the IF chain, and the current crystal filter becomes a second roofing filter.

Also, it would seem with DSP technology, filters, noise reduction and such would be possible in ways that were never possible with tried and true crystal filters and analog techniques. Have DSP audio processors delivered on these possibilities?

My old school HF transceiver has a narrow CW crystal filter and it seems to work well, but for my UBitx maybe something new school would be more practical.

In a field day situation if a high power station was near by in distance and frequency it could help. But if the radio was good enough to not overload, in that case, is it due to the crystal filter or simply the design of the receiver can handle a high dynamic range?

Are there any good articles or comparisons of one over the other? I'd been thinking of adding a audio bandpass filter to my UBitx, but sounds like it is not difficult to add a narrower crystal filter if done in "parallel" as suggested here. The difference in IF frequency seems like it would just be a software change, unlike radios of old. 

Tom, wb6b

starting point

dgclifford@...
 

hello  i have just ordered my ubitx and i am wondering where  to start ,should i go with the original stuff first or update  asap any ideas on a logical progression would be great .i have a couple of spare (gifts) raspberry pi 3b that are doing nothing what would be a good use for these . purchasing the ubitx was an spur of the moment i now would like to plan the way forward a bit more than i have.  many thanks dave c

Re: Narrow filter for CW #ubitxcw

Ashhar Farhan
 

If close in signals are not a worry then certainly a digital filter is indicated. The one large advantage of a digital filter is that there is no phase distortion. Thus ringing is minimum. But you need a very good 24 bit codec.
- f

On Tue 13 Aug, 2019, 12:30 PM Tom, wb6b, <wb6b@...> wrote:
Hi,

Are there any comparisons that would indicate if a narrower bandwidth crystal filter verses an audio bandpass filter perform better? In some ways the audio filter is just another filter in the IF chain, and the current crystal filter becomes a second roofing filter.

Also, it would seem with DSP technology, filters, noise reduction and such would be possible in ways that were never possible with tried and true crystal filters and analog techniques. Have DSP audio processors delivered on these possibilities?

My old school HF transceiver has a narrow CW crystal filter and it seems to work well, but for my UBitx maybe something new school would be more practical.

In a field day situation if a high power station was near by in distance and frequency it could help. But if the radio was good enough to not overload, in that case, is it due to the crystal filter or simply the design of the receiver can handle a high dynamic range?

Are there any good articles or comparisons of one over the other? I'd been thinking of adding a audio bandpass filter to my UBitx, but sounds like it is not difficult to add a narrower crystal filter if done in "parallel" as suggested here. The difference in IF frequency seems like it would just be a software change, unlike radios of old. 

Tom, wb6b

Re: Narrow filter for CW #ubitxcw

Dennis Zabawa
 

Here is another alternative for the audio side: Variable Audio Filter

Re: starting point

Dean Souleles
 

Hi Dave - 

Great question and one I should have asked - hi hi.   As a brand new kit builder and having just finished my build - and still debugging a few problems, here is my advice.  Build the kit stock and make sure everything is working before you do any mods.  I bought the amtateurradiokits case (which I love) at the same time I bought the board - and one of my issues has been case integration (mostly caused by my inexperience). I built it straight into the case without a smoke test which meant that when things weren't working I had one more variable to deal with - is the case or the ubitx the problem.  For example once I got the build complete and turned it on the first thing I noticed was the audio was garbled and the frequency display appeared off - but hard to tell because the audio was so bad.  After a bunch of fiddling - and with help from the group here - I got it down to the BFO calibration - about a 5 minute fix once I knew what to do.  I got lots of advice about doing things to the hardware - but believing that the simplest explanation is usually the correct one - I kept double checking my work and found a mistake or two.   Second issue I had  (haven't fixed yet) is I think I miss-wired - or sloppy soldered the mic connection on the expansion PCB that came with the case.  Again - if I had tested the ubitx prior to wiring it up to the case I would know where to look.

It will be much easier to mod a working radio then to debug a mélange of original kit and after-market mods.

My two cents from the cheap seats.

Dean
KK4DAS